Projects / Programmes
Napovedna vrednost oksigeniranosti tumorjev pri izbranih bolnikih z malignomom glave in vratu (Slovene)
| Code |
Science |
Field |
Subfield |
| 3.04.00 |
Medical sciences |
Oncology |
|
| Code |
Science |
Field |
| B200 |
Biomedical sciences |
Cytology, oncology, cancerology |
tumor oxygenation, intratumoral oxygen monitoring, head and neck cancer, radiotherapy, altered fractionation, carbogen and nicotinamide, prognostic value
Researchers (11)
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0302 |
Institute of Oncology Ljubljana |
Ljubljana |
5055733000 |
15,471 |
Abstract
The method of tumo r oxygenation measurement for clinical use is opening new possibilities of individual treatment planning. The results of studies carried out on cell cultures and experimental animals have proved that the hypoxic environment significantly reduces the effects of radio- and chemotherapy on clonogenic tumor cells. The tumor volumes seen in clinical conditions are generally much greater than those dealt with in experimental conditions. Therefore, the possibility of hypoxic areas occurrence is proportionally greater, and the associated negative effects of hypoxia on treatment success even more relevant. Lacking tumor oxygenation is atributable to insufficient blood supply and increased oxygen consumption due to the rapid proliferation of clonogenic cells. It is the very hypoxic environment that the tumor cells respond to with even more enhanced proliferation. Since the faster kynetics of cell division is associated with a greater possibility of locoregional recurrence as well as of the ocurrence of distant metastases, the hypoxia measured in the tumors yields a prognostic value not only in the irradiated patients but also in those treated by surgery as primary treatment. The problem is further complicated by simultaneous occurence of acute and chronic hypoxia, each of these being caused by thoroughly different mechanisms. In experimental conditions, carbogen inhallation (1-5% mixture od CO2 plus oxygen) combined with simultaneous application of high dose nicotinamide was found to increase both tumor oxygenation as well as the effect of radio- and chemotherapy, although the procedure has not been clinically evaluated yet. The proposed project will include selected, previously untreated patients with head and neck tumors; the tumors must be accessible to intratumoral oxygenation measurements, which will be aimed:
- to measure objectively the total volume of tumor burden and the regions with poor blood supply
- to evaluate the extent of neovascularization and tumor proliferation by means of histological and immunohistological methods
- to determine the range of tumor oxygenation value, which will help us to distinguish between the prevailingly hypoxic tumors and the better oxygenized ones
- to define the most effective combination of carbogen and the optimal daily dose of nicotinamide.
The group of patients with hypoxic tumors will have the selected therapy combined with daily applications of nicotinamide and hyperoxygenation with carbogen. Our basic aim is to study measurements, as well as to evaluate the importance of additional oxygenation in different therapeutic protocols. It is expected that the invasive method of tumor oxygenation determination will prove prognostically relevant enough to be used for individual treatment planning in patients with head and neck tumors.
